This invention relates to improvements in monitoring the status of remotely located apparatus, and particularly to such a system employing electronic means for monitoring the status of a multiplicity of data points with a minimum of interconnections.
In subsea petroleum well control systems, as well as other similar type systems, the status of valves or other devices need to be known for proper operation of the system. Generally, these status points are remotely located from the basic control module and transferring this data into the module requires an electrical interface.
In some subsea control modules, it has been found desirable to perform electrical interface by means of inductive couplers, whose numbers are limited due to size restrictions in the flange connecting a control module to the well structure. The number of desired status readings sometimes greatly exceed the number of couplers available so that each coupler must handle a number of status points.
It would be possible to employ small external modules to process this information and transfer it to the control module, but this would unduly increase the complexity of the system as well as require power for handling the active devices in such a module. It would be desirable to handle the required data as simply as possible with a high degree of reliability.